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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node76.html b/sag-0.6.1-www/Invisible/sag-0.6/node76.html new file mode 100644 index 0000000..3fc9d01 --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node76.html @@ -0,0 +1,80 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> +<!--Converted with LaTeX2HTML 96.1-h (September 30, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> +<HTML> +<HEAD> +<TITLE>Run levels</TITLE> +<META NAME="description" CONTENT="Run levels"> +<META NAME="keywords" CONTENT="sag"> +<META NAME="resource-type" CONTENT="document"> +<META NAME="distribution" CONTENT="global"> +<LINK REL=STYLESHEET HREF="sag.css"> +</HEAD> +<BODY LANG="EN" > + <A NAME="tex2html1269" HREF="node77.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1267" HREF="node73.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1261" HREF="node75.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1271" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1272" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1270" HREF="node77.html">Special configuration in /etc/inittab</A> +<B>Up:</B> <A NAME="tex2html1268" HREF="node73.html">init</A> +<B> Previous:</B> <A NAME="tex2html1262" HREF="node75.html">Configuring init to start </A> +<BR> <P> +<H1><A NAME="SECTION00830000000000000000">Run levels</A></H1> +<P> + A <b>run level</b> is a state of <tt>init</tt><A NAME="2432"> </A> and the whole + system that defines what system services are operating. Run + levels are identified by numbers, see table <A HREF="node76.html#tabrunlevels">7.1</A>. + There is no consensus of how to use the user defined run levels + (2 through 5). Some system administrators use run levels to + define which subsystems are working, e.g., whether X is running, + whether the network is operational, and so on. Others have all + subsystems always running or start and stop them individually, + without changing run levels, since run levels are too coarse + for controlling their systems. You need to decide for yourself, + but it might be easiest to follow the way your Linux distribution + does things. +<P> + <P><A NAME="2242"> </A><A NAME="tabrunlevels"> </A><IMG WIDTH=381 HEIGHT=89 ALIGN=BOTTOM ALT="table2241" SRC="img12.gif"><BR> +<STRONG>Table 7.1:</STRONG> Run level numbers<BR> +<P> +<P> + Run levels are configured in <tt>/etc/inittab</tt><A NAME="2434"> </A> by lines like + the following: +<BLOCKQUOTE> <TT> +l2:2:wait:/etc/init.d/rc 2 +</TT></BLOCKQUOTE> + The first field is an arbitrary label, the second one means + that this applies for run level 2. The third field means that + <tt>init</tt><A NAME="2436"> </A> should run the command in the fourth field once, + when the run level is entered, and that <tt>init</tt><A NAME="2438"> </A> should wait + for it to complete. The + <tt>/etc/init.d/rc</tt><A NAME="2440"> </A> command runs whatever commands are necessary + to start and stop services to enter run level 2. +<P> + The command in the fourth field does all the hard work of + setting up a run level. It starts services that aren't already + running, and stops services that shouldn't be running in the + new run level any more. Exactly what the command is, and how + run levels are configured, depends on the Linux distribution. +<P> + When <tt>init</tt><A NAME="2442"> </A> starts, it looks for a line in <tt>/etc/inittab</tt><A NAME="2444"> </A> + that specifies the default run level: +<BLOCKQUOTE> <TT> +id:2:initdefault: +</TT></BLOCKQUOTE> + You can ask <tt>init</tt><A NAME="2446"> </A> to go to a non-default + run level at startup by giving the kernel a command line + argument of <tt>single</tt> or <tt>emergency</tt>.<A NAME="tex2html36" HREF="footnode.html#2312"><IMG ALIGN=BOTTOM ALT="gif" SRC="./foot_motif.gif"></A> This allows you to choose + the single user mode (run level 1), which is described in + section <A HREF="node78.html#secsingleusermode">7.5</A>. +<P> + While the system is running, the <tt>telinit</tt><A NAME="2448"> </A> command can change + the run level. When the run level is changed, <tt>init</tt><A NAME="2450"> </A> runs + the relevant command from <tt>/etc/inittab</tt><A NAME="2452"> </A>. +<P> +<HR><A NAME="tex2html1269" HREF="node77.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1267" HREF="node73.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1261" HREF="node75.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1271" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1272" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1270" HREF="node77.html">Special configuration in /etc/inittab</A> +<B>Up:</B> <A NAME="tex2html1268" HREF="node73.html">init</A> +<B> Previous:</B> <A NAME="tex2html1262" HREF="node75.html">Configuring init to start </A> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |